What is the proper lawn sprinkler watering schedule for Dallas, Fort Worth, and North Texas? There are many opinions about this, most of which are vague and overgeneralized. Example: "Your grass needs 1 inch of water per week."
Take a look at the 2023 USDA Plant Hardiness Map.
Almost anywhere you go, you will hear turfgrass needs "1 inch of water per week." Neil Sperry states it, most documents from Texas A&M state it, Oklahoma State says it, Kansas State says it, etc. Question: do they have 5-months of summer in Omaha? Do they have nighttime temps in Kansas City at 88 degrees in July? Do they have St. Augustine grass in Denver? No. Therefore, how can this be true? Answer: they are just averaging water totals for the year, trying to come up with something simple for people to digest. Is "simple" the best for our warm-season turfgrass in North Texas? No. In fact, it actually hurts the grass greatly, as most people take this over-simplification literally.
As a consultant for soil and turfgrass diseases, we have found the following to be true: property owners overwater in the Fall, Winter, and Spring, contributing to all kinds of fungal diseases. Then they drastically underwater in the Summer. Why? Part of it is due to the "1 inch" problem. And part of it is due to people wanting to "set it and forget it." Like with most things in life, you will get out of it what you put into it. Our irrigation lawn watering guide requires changing your watering schedule 5 times per year.
March 15 to April 15 - Mist Heads - 20-25 minutes per week, for every zone, and 40-50 minutes for Rotor Head zones. It is broken up into four cycles on two days (whatever your water days are). Example: Tuesday - 5 AM for 5 minutes, then 7 AM for 5 minutes. Friday - 5 AM for 5 minutes, then 7 AM for 5 minutes.
April 15 to May 15 - Mist Heads - 30-35 minutes per week, for every zone, and 60-70 minutes for Rotor Head zones. It is broken up into four cycles on two days (whatever your water days are). Example: Tuesday - 5 AM for 8 minutes, then 7 AM for 8 minutes. Friday - 5 AM for 8 minutes, then 7 AM for 8 minutes.
May 15 to July 4 - Mist Heads - 45 minutes per week, for every zone, and 90 minutes for Rotor Head zones. It is broken up into four cycles on two days (whatever your water days are). Example: Tuesday - 5 AM for 11 minutes, then 7 AM for 11 minutes. Friday - 5 AM for 11 minutes, then 7 AM for 11 minutes.
July 4 to Sept 10 - Mist Heads - 55-60 minutes per week, for every zone, and 120 minutes for Rotor Head zones. It is broken up into four cycles on two days (whatever your water days are). Example: Tuesday - 5 AM for 15 minutes, then 7 AM for 15 minutes. Friday - 5 AM for 15 minutes, then 7 AM for 15 minutes.
Sept 15 (if heat/drought has broken; if not, continue with July 4 times until it does) to October 15 - Mist Heads - 45 minutes per week, for every zone, and 90 minutes for Rotor Head zones. It is broken up into four cycles on two days (whatever your water days are). Example: Tuesday - 5 AM for 11 minutes, then 7 AM for 11 minutes. Friday - 5 AM for 11 minutes, then 7 AM for 11 minutes.
October 15 to November 15 - back to 30-35 minutes per week, for every zone, and 60-70 minutes for Rotor Head zones. It is broken up into four cycles on two days (whatever your water days are). Example: Tuesday - 5 AM for 8 minutes, then 7 AM for 8 minutes. Friday - 5 AM for 8 minutes, then 7 AM for 8 minutes.
Note #1 - unless we are in extreme drought in the Winter, never water your warm-season turfgrass in the Winter. Let the acidic rainwater help bring your soil PH back down, flush out chlorine, etc.
Note #2 - if it rains the same equivalent amount in the Spring or Fall, you can shut your water off. For example, we got 1/3rd of an inch of rain on March 15. Cancel your irrigation for that week.
Note #3 - do not shut your irrigation water off in DFW from June (late)-to September, even if we get rain. Our heat is so brutal, and the subsoil gets so dry that your trees and foundation need the additional moisture. Further, once subsoil gets bone dry, then the irrigation water you put on the topsoil gets wicked out like you put it on the Sahara Desert.
Note #4 - this staggered irrigation schedule saves water in the early months, so we can pour on additional water in the months our black clay turns to dry powder and when the turfgrass needs it most, which means ½ inch in early Spring up to 1.25 inches in July-September.
Note #5 - the September period is always the iffy one, as it depends on the year's heat and the drought level. If we are in a severe/exceptional drought (like 2023), then it will take a long time to re-establish the subsoil moisture, 2-5 feet down.
Note #6 - the best time to water is from 5 AM to 9 AM. Unless watering in a fertilizer or a chem, never water in the evening (no matter what your lawn guy or irrigation guy tells you). That said, if you have a lot of rotor head zones, you will have to start watering earlier due to the length of time it will take to water all of your zones. So, in this instance, you can go back to 3 AM if you need to do it.
Note #7 - if you have a zero lot line property, with two-story houses on both sides, you will probably only get 1-3 hours of sunlight in that section. You are never going to grow warm-season turfgrass there, so there will be no turfgrass to use the water and little sun to dry the area out. Therefore, adjust the runtimes in those specific zones (where nothing is growing) to the point where it is not muddy two days after it runs.
Note #8 - we don't recommend buying water saving nozzles on mist heads, in North Texas. You have to run your irrigation 2-3X longer. The turfgrass needs the amount of water it needs. It does not care about political or city agendas.
Note #9 - most people are never told by their irrigation guy that average rotor heads put out 50-60% less water than mist heads. Our irrigation runtimes are based on putting out rain gauges on more than 100 properties to check the amount of water being output on mistheads vs. power rotor heads. If you want to know the exact amount of water being put out on your property then put out several rain gauges or tuna cans and run a test for 10 minutes. Measure the amount of water in the various receptacles and calculate how many minutes you need to run your irrigation system to get to the inches of water required in the various months.